Russia moving in under the pretense of ridding the region of ISIS is like the Mafia moving to your neighborhood under the pretense of moving out a violent street gang, then setting up a permanent base there to do Mob business.
Russia will grow wealthier, more powerful, more aggressive in their overall expansionist agenda (Eastern Europe, eventually elsewhere), and much more of a threat to the US and its allies throughout the region and the world.
Sure its great IF they actually do get rid of ISIS (we shall see). But having a country like Russia step in and gain such huge strategic advantage over the US and its allies is nothing we should be cheering about.
If Obama was serious about wanting to take out ISIS, which I dont believe he ever wasI think him and Putin are actually in cahoots on this whole thing despite his and Kerrys public moans and groans about it, it might not ever have come to this. But then Russia would likely have come up with some other rationale or excuse for moving into Syria and taking control of it, and ultimately the entire Middle East. Makes me wonder if ISIS was a KGB-like invention of the Russians, created to give them cover for expanding.
Putin has stated that he believes the demise of the (mass-murdering, communist [my words]) Soviet Union was the "worst geopolitical catastrophe of the 20th century". He has also said he thinks Stalin deserves to have statues in his honor. He clearly seeks to restore the old Soviet Union, or something not too far different from it.
The bottom line is you have two choices for who rules the ME. Russia or ISIS. The dictators can’t hold out against ISIS. And all we want to do is help them take out the dictators. I have to choose Russia.